基于线路参数在线校正的能量平衡保护

由于整定的线路参数与实际线路参数存在一定误差,基于3个空间模量的能量平衡保护若按整定的参数计算能量,外部故障时采用2种方法计算的能量曲线会有很大的误差,降低了能量平衡保护的可靠性。文中提出线路电阻采用整定值,线路电感和电容采用3个模分量参数计算平均值的校正方法,从而得到较准确的实际线路参数。1000kV特高压线路动模实验表明,该方法较好地消除了由于参数误差引起的外部故障时2种方法计算的能量曲线差异,能量平衡保护在各种复杂故障情况下仍能正确保护线路,单相接地故障时具有选相功能。

Energy Balance Protection Based on Online Calibration of Transmission Line Parameters

Owing to the inconsistency between the actual line parameters and the preset parameters, if the energy is calculated by the preset parameters for the energy balance protection based on three spatial modules, there will be very big errors for the two energy curves of the external fault, reducing the reliability of energy balance protection. A method of transmission line resistance using the preset values and transmission line inductance and capacitance using the corrected average value of the three modules is presented, which yields fairly accurate actual line parameters. Dynamic simulation experiments on the 1000 kV transmission line show that the two energy curves of the external fault are consistent with each other. Whatever complex fault conditions of the power system, excellent performance is ensured with energy balance protection based on three spatial modules for its capability of switching off the faulty phase should a single line-to-ground fault occur.